Process for flocculating using a poly(quaternary ammonium)polyether polyelectrolyte

ABSTRACT

Water-soluble poly(quaternary ammonium) polyether polyelectrolyte salts containing quaternary nitrogen atoms in the polymer backbone and chain-extended by ether groups are prepared by treating the polymeric reaction product from an N,N,N&#39;&#39;,N&#39;&#39;tetraalkyl-hydroxy substituted diamine and an organic dihalide such as a dihaloalkane or a dihalo ether with an epoxyhaloalkane. These polyelectrolytes are used in processes for flocculating particles dispersed in aqueous media, for example, white water clarification, clay flocculation, sewage treatment, and wet-end addition, by adding the polyelectrolyte to the aqueous media in amounts sufficient to flocculate the dispersed particles.

United States Patent [1 1 Win [451 Aug. 28, 1973 1 PROCESS FORFLOCCULATING USING A POLY(QUATERNARY AMMONIUM)POLYETHER POLYELECTROLYTE[75] Inventor: Edward Witt, Dover, Del.

[73] Assignee: Polysar International, S.A.,

- Fribourg, Switzerland 221 Filed: Sept. 29, 1971 21 App1.No.: 184,964

Related u.s. Application Data [60] Division of Ser. No. 51,344, June 30,1970, Pat. No. 3,663,461, which is a continuation-in-part of Ser. No.763,977, Sept. 30, 1968, abandoned.

[52] US. Cl 210/54, 162/164, 162/190 [51] Int. Cl C02b l/20 [58] FieldofSearch ..210/52 54; 162/164, 190;

[56] References Cited UNITED STATES PATENTS 2.995.512 8/1961 Weidner etal. 210/54 3,219,578 ll/1965 Cruickshank et a1 210/52 PrimaryExaminer-Michael Rogers Attorney- Don O, Winslow, Roger L. Hansel etal.'

[5 7 ABSTRACT Water-soluble poly(quaternary ammonium) polyetherpolyelectrolyte salts containing quaternary nitrogen atoms in thepolymer backbone and chain-extended by ether groups are prepared bytreating the polymeric reaction product from anN,N,N',N'-tetraalkyl-hydroxy substituted diamine and an organic dihalidesuch as a dihaloalkane or a dihalo ether with an epoxyhaloalkane. Thesepolyelectrolytes are used in processes for flocculating particlesdispersed in aqueous media, for example, white water clarification, clayflocculation, sewage treatment, and wet-end addition, by adding thepolyelectrolyte to the aqueous media in amounts sufficient to flocculatethe dispersed particles.

12 Claims, No Drawings PROCESS FOR FLOCCULATING USING A POLY(QUATERNARYAMMONIUMWOLYETIIER POLYELECTROLYTE CROSS-REFERENCETO RELATEDAPPLICATIONS BACKGROUND OF THE INVENTION This invention relates topoly(quaternary ammonium) polyether polyelectrolyte salts that containquaternary nitrogen in a polymeric backbone and that are chain-extendedby ether groups and their preparation from water-soluble poly(quaternaryammonium salts) containing pendant hydroxyl groups and bifunctionallyreactive chain-extending agents. This invention further relates toprocesses for flocculating particles dispersed in aqueous media, e.g.,processes for white water clarification, clay flocculation, wet-endaddition during paper making, and sewage treatment, by adding thepolyether polyelectrolytes to the aqueous media in amounts sufficient tocause flocculation.

In the flocculation of particles from aqueous media, for example, in thepaper making art, a number of agents are known which function asretention aids for both additives and fiber fines. Among the agentsknown are starch, ether and ester derivatives containing hydrophilicgroups, cationic amine starch derivatives, co-

polymers from acrylamide and acrylic acid, and polyethylenimine. Theseagents, particularly those containing tertiary amino groups having astrong positive charge at the nitrogen atom, tend to adhere byelectrostatic attraction to cellulosic substrates which are in generalnegatively charged. Thus, in'wet-end sizing of paper, low levels ofthese agents or retention aids may be used to cause nearly completeretention of the mineral filler and fiber fines in the paper web beingformed on the rapidly-moving paper machine wire. The sizing material orretention aid added in the feeder or head box is thus highly substantiveto the fibers in'the paper web and is of great value for promotinginterfiber bonding. Another function of these agents is improveddewatering of the paper stock which leads to faster drainage, higher wetweb strength, and lower steam consumption during the drying process.

An allied problem in paper technology is the clarification of whitewater, that is, the effluent material coming from the web forming anddrainage procedures that contains finely colloidally dispersedpigmentary and fibrous waste which must be removed before the effluentcan be discharged into a stream or sewage-treatment plant. It isadvantageous to remove this waste even when the white water is beingrecycled. Often polymeric flocculants or coagulants are used to removethis waste. When pigments or fillers are a component of the effluent, itis most advantageous to coagulate and also to recover these valuablematerials.

In the mining and metallurgical arts, flocculating agents are frequentlyused to recover ores from suspensions in water. The aggregated fineoresare recovered, while at the same time the water is clarified. Theadvantages of using a flocculant in these systems are both the increasedsettling rate and the enhanced filtration rate of the resultingclarified water system. If no flocculating agent is used in thesesettling operations, only the heavier solid particles settle at thebottom of the chamher in a reasonable length of time, while theremaining finely divided colloidal material is suspended in thesupernatant liquor, often for days. Also, various flocculating agentsare useful in clay benefication, particularly in treating clays used indrilling muds.

I-Ieretofore several problems have been encountered with the knownflocculants or coagulants used for sepa- 1 rating dispersed particlesand the like materials from aqueous media. One problem is thatexcessively large amounts of the flocculant are often required to effectthe desired separation or settling out of the dispersed materials. Whenthis problem is 'overcome by the use of a more efficient flocculant, itmay be difficult to con-. trol the viscosity of the flocculant at theconcentrations required for the intended application or the flocculantmay be too costly and/or not readily available. The cost factor isparticularly troublesome where the primary purpose of the watertreatment is for pollution control such as in sewage treatment. In thisregard, it is evident from the current interest in environmentalimprovement that pollution of waterways, such as streams, rivers, lakes,etc. is an increasing problem that must be solved by many industries ingeneral and particularly those which produce aqueous wastes requiringthe use of flocculants and coagulants.

SUMMARY OF THE INVENTION Advantageously this invention provides cationicpolyelectrolytes which overcome many of the problems of the knownpolymeric flocculantsand coagulants. Thus, this invention contemplatespoly(quaternary ammonium) polyether polyelectrolyte salts containingquaternary nitrogen atoms in a polymeric backbone which are highlyefficient flocculants. These salts are prepared by treating thepolymeric reaction product from anN,N,N.,N'-tetraalkyl-hydroxyalkylenediamine and an organic dihalide suchas a dihaloalkane or a dihaloether with an epoxy haloalkane.

This invention is further directed to a method for preparing thesepolymeric water soluble polyether polyelectrolyte salts which comprisesreacting the reaction product of theN,N,N,N'-tetraalkyl-hydroxyalkylenediamine and the organic dihalide at atemperature of from about 50C. to about C. in the presence of analkaline material in an aqueous reaction medium containing sufficientwater to regulate the viscosity of the resulting water-soluble product.

This invention also is c'oncemed with a process for treating adispersion of particles in an aqueous medium to flocculate theparticles, which includes the step of admixing'an aqueous dispersion ofparticles with the cationic N-containing polymeric polyelectrolyte insufficient amounts to flocculate the particles. Usually from about 1.0to 5.0 parts by weight of flocculant per millionparts by weight of theaqueous dispersion will obtain excellent separation.

Thus it will be recognized that one advantageous result of thisinvention, which is of particular importance, is that the chain-extendedpoly(quaternary ammonium) polyethers used as flocculating agents show avery high efficiency for eflecting flocculation or coagulation ofparticles dispersed in an aqueous medium.

The polymeric poly(quaternary ammonium) polyethers of this inventionhave a repeating unit of the following general formula:

wherein R is a lower alkyl group, particularly an alkyl group containingone-four carbon atoms; R. is the residue of a hydroxy-substitutedalkylene group containing up to about carbon atoms; R" is a loweralkylene group, particularly an alkylene group containing onefour carbonatoms such as methylene, ethylene, propylene, butylene, or anoxaalkylene group (CH,),,-O- (CH where n is an integer from 1 to 4; R'is an alkylene group, particularly methylene, ethylene, propylene, orbutylene; R"" is an R residue of the same or different polymeric chainor a terminal hydrogen group and A is an anion such as chloride, bromideor iodide.

These poly(quaternary ammonium) polyether polyelectrolytes are derivedfrom the reaction products of tetraalkyl hydroxydiamines of the generalformula:

wherein R and R are the organic groups defined in formula I above withapproximately an equimolar proportion of an organic dihalide having thegeneral formula:

wherein A represents the anions and R represents the organic radicalsheretofore defined in formula I, this reaction may be represented by thefollowing equation:

organic dihalide is used in excess of equi-molar proportions in order toincrease the reaction rate.

The tetraalkylated hydroxy diamine designated by formula II can beprepared by various reaction routes. One particularly effective routeinvolves reacting an aqueous solution of a dialkylated secondary amine,such as dimethylamine, with a bifunctional compound, such asepichlorohydrin; 1,3 dichloro-2-propanol; 4- chloro-l,2-epoxy-butane;bis (epoxyethyl) ether; and the like. In general, at least three molesof the secondary amine are used per mole of the difunctional compound.

When a chloro-containing difunctional compound is used in thepreparation, the amine hydrochloride produced is removed by treatmentwith a base, such as sodium hydroxide. Excess water and the secondaryamine are removed by vacuum stripping.

The ditertiary amine is extracted with ethanol or like polar-typesolvents from the resulting residual salt slurry. The ethanol is removedby vacuum distillation. The pure ditertiary amine is then obtained byvacuum distillation.

Exemplary of the tetraalkyl diamines that can be used to prepare thepoly( quaternary ammonium) intermediates for preparing the flocculantsor coagulants of this invention are N,N,N',N-tetramethyl-2-hydroxyl-1,3-propane diamine; N,N,N,N-tetraethyl-3-hydroxy- 1,4-butane diamine;N,N,N',N'-tetramethyl-2,3- dihydroxy-l,4-butane diamine; and the like.

The organic dihalides which are reacted with the tetraalkyl hydroxydiamines include beta, betadichlorodiethyl ether; l,2-dichloroethane;1,2- dibromoethane, (ethylene dibromide); 1,3 dibromopropane;1,4-dichlorobutane; 1,4-diiodobutane; and the like.

In preparing the intermediate poly(quaternary ammonium salts), water isemployed in amounts sufficient to insure solution of the reactionproduct and to adjust viscosity. In general, from about 50 parts to 100parts by weight of water are used per 100 parts of the reactants. Uponcompletion of the reaction, the resulting poly(quaternary ammonium salt)may be used in solution as prepared or may be dried to form a highlyhygroscopic, resinous, light yellowish-brown product.

It has been found that a particularly useful intermediate forpoly(quaternary ammonium) polyether polyelectrolyte compositions of thisinvention are obtained by reacting dichlorodiethyl ether with N,N,N',N'-tetramethyl-Z-hydroxy-l ,3-propane diamine in approximately equimolarproportions at temperature of to C. and in an aqueous medium for 6hours.

Poly(quaternary ammonium salts) useful in preparing the coagulatingagents of this invention may be prepared by the reaction between ahydroxydihaloalkane derivative and a tetraalkyldiaminoalkane derivativeby the following reaction:

where R, R, and R" represent the organic radicals defined in formula (I)and A represents the anion. Examples of dihalo compounds useful for thispurpose include l,3-dichloro-Z-hydroxypropane, l,3-dibromo-2-hydroxypropane, 1,4-dichloro-2-hydroxybutanebis(2-chloro-l-hydroxyethyl) ether, and the like.

Tetraalkyldiamines useful in this synthesis includeN,N,N,N'-tetramethyl-l ,Z-ethane diamine, N,N,N',N-'-tetraethyl-1,5-pentane diamine, N,N,N,N- tetramethyl-l ,6-hexanediamine, bi's-( N,N- dimethylaminoethyl) ether, and the like.

The polyether polyelectrolytes of this invention are preferably made bythe reaction between a poly(quaternary ammonium) polyelectrolyte of thetype designated by formula (IV) containing a hydroxyl substituent and anepoxyhaloalkane such as epichlorohydrin. The first step of the reactionwith an epoxyhaloalkane is represented as follows:

R t l u A- R in which the epoxide reacts with a pendant hydroxyl group.The product obtained has a reactive halide which, when R is methylene,reacts with the alkaline reagent, e.g., sodium hydroxide, to form anepoxy group. The epoxy group may then react with a hydroxy group on apolymericbackbone of the polyelectrolyte to cause chain-extension of thepolyelectrolyte. Alter-' It has been determined that the use of fromabout l.l to about 2.3 moles of epihalohydrin per mole of repeatingpoly(quaternary ammonium) intermediate (lV) (hereinafter referred to asPolyquat) gives higher polymer solution viscosities, even at low solidslevels, than those of the starting high-solids Polyquat solution. Veryviscous solutions are obtained when from about 1.1 to about 1.7 moles ofepihalohydrin are used per mole of repeating Polyquat unit. Despite thehigh viscosity of the solutions, they are completely gel-freeflt will beappreciated that the amount of chain-extension by cross-linking must becontrolled in order to obtain such gel-free products. At higher ratiosof epihalohydrin to Polyquat, it has been found that substantiallynatively, the epoxy group may react with water in the presence of thealkaline material to form a hydroxy group.

Epoxyhaloalkanes useful in preparing the materials of this inventioninclude epichlorohydrin (l-chloro- 2 ,3-epoxypropane l-bromo-2,3-epoxypropane l-chloro-3 ,4-epoxybutane, 2-chloro-5 ,-epoxy-hexane,1,2-epoxy-6-iodohexane, and the like. Epichlorohydrin is particularlypreferred for purposes of this invention for reasons of economy andavailability.

An alkaline reagent or material must be used to pro mote thechain-extension reaction with an epoxyhaloal- 1 kane. This reagent is analkali metal hydroxide or an alkaline earth metal oxide or hydroxide.Sodium hydroxide is a particularly effective reagent for this reason.

The Brookfield viscosity of the resulting polymer solution, determinesthe enhanced usefulness of the polyether polyelectrolytes asflocculating agents. This viscosity is critically dependent on theconcentrations of water, epoxyhaloalkane, and alkaline reagent used, aswell as on the reaction temperatures employed during formation of thechain-extended polyelectrolytes.

Thus it has been found that a number of parameters critically affect thechain-extending reaction of this invention. The influence of the amountof water, epoxyhaloalkane, and alkaline material to the amount ofreaction product from the tetraalkyl-hydroxyalkylenediamine and analpha, omega-dihalo-alkane derivative with epichlorohydrin, as well asthe effect of reaction temperatures and times must be carefullycontrolled. 1

increased product solution viscosities, up to a ratio of about 2.3 molesof'epihalohydrin per mole of Polyquat unit are obtained. Above thisepihalohydrin to Polyquat ratio, the products are more viscous than thestartdroxide per mole of Polyquat repeating unit is particularlyeffective. However, ratios of from 0.75 to about 1.6 moles of sodiumhydroxide per mole of Polyquat unit give significant increases insolution viscosities.

It will be understood that the chain-extension reaction betweenPolyquats and an epihalohydrin is also dependent on the reactiontemperature. A particularly advantageous reaction temperature, usingincreasing product solution viscosity as a criterion, is about C.However, chain-extension may be effected at reaction temperaturesbetween 60 and C. At 80C. and above there is a decrease in thechain-extending reaction. it is believed that the reason for thedecrease in chain-extension during the reaction at 80C. results from acompeting epihalohydrin hydrolysis reaction to produce the glycolgroupings which are unreactive with the hydroxyl groups on thePolyquats.

Of the several experimental parameters related to preparing thepolyether polyelectrolytes, the amount of water added both initially andduring the course of the chain-extension reaction is exceedinglycritical. Water is charged to the reaction vessel at first to dissolvethe sodium hydroxide or other alkaline reagent. In-a system employingepichlorohydrin as the chain-extending agent and sodium hydroxide, themost viscous polymer solutions are obtained when about 10 moles of waterare used per mole of Polyquat repeating unit. When less than this amountis used, the product is gelatinous. At levels of initial water additionabove about 12 moles of water per mole of Polyquat unit, thechain-extension reaction is limited as evidenced by the fact that thein-- crease in solution viscosity is slight.

As the chain-extension reaction proceeds, the resulting solutions becometoo viscous for proper agitation, so that water must be added to give aworkable viscosity. The amount of water which must be added variesbetween about 25 and about 60 moles of water per mole of Polyquat unitsand the manner in which this water is added has profound influence onthe resulting solution properties. When this water is added early in thereaction, that is soon after the mixture of water, alkaline reagent,epihalohydrin, and Polyquat is charged to the reaction vessel, thereaction products are markedly less viscous than when water is addedlater in the reaction run. It has also has been found that theincremental addition of water of dilution is helpful in attainingsolutions with very high viscosities. For convenience, it isparticularly preferred to add this water by a programmed additionprocedure using a metering injection pump.

In order to estimate molecular weights of the Polyquats and theirchain-extended derivatives of this invention, intrinsic viscosities ofselected samples were determined at 25C. in 0.4 M KCl and 0.4 M KBr.This is done by preparing dilute solutions of the polymers in the mediumand determining their specific viscosities (m where 1; equals t/t-1where t is the time of flow for a solution of concentration C and t isthe flow time for the pure solvent. A plot of rm/C yields a straightline of which the intercept is intrinsic viscosity [1;]. The intrinsicviscosity of a typical starting material, i.e., the reaction product ofN,N,N,N'-tetramethyl-2-hydroxy- 1,3-propane diamine and dichloroethylether, in 0.4 M KCl varied between 0.06 and 0.22 (In 0.4 M KBr, theviscosity was 0.17). Based on the observation that the intrinsicviscosity was 0.22 grams per deciliter for an ionene, i.e.

chain-extended polyelectrolytes varies from about 0.25

to about 0.60 in 0.4 KBr at 25C.

The polyether polyelectrolytes of this invention are particularly usefulas flocculating agents for finely divided mineral materials, such asclay. Chain-extended Polyquats with Brookfield viscosities in the rangebetween about 100 and about 25,000 centipoises at roughly 30 percentcontent are especially effective as flocculating agents. It has beenfound that polyether polyelectrolytes with Brookfield viscosities belowabout 25,000 centipoises are more effective as flocculants than higherviscosity polyether polyelectrolytes or than the starting Polyquats.Polyether polyelectrolytes in this preferred viscosity range comparevery favorably in efficiency with flocculants now commerically in use,even at low levels of addition of the range between 1 to 5 parts permillion.

The polyether polyelectrolytes are also useful as clarification aids forwhite water, as from paper making. Adding as little as 0.1 to 1.0 partsper million of the polyelectrolytes results in significant clarificationof white water, to levels of transmission of light at 530 m of aroundpercent or even higher. These results compare quite favorably to thoseobtainable with commercial clarification aids, such as Tylite No. 9.

Moreover, the polyelectrolyte solutions function well as pigmentretention aids in wet-end addition during paper making. The polymersolutions, when added at levels of between 0.5 lb. and 1.0 lb. per tonof papermaking slurry, result in paper products containing upwards of 30percent, and even as high as 45 percent, of retained pigment asdetermined by combustion ash. These results are within the rangesachieved by presently used flocculants; in many cases higher pigmentlevels in the paper are attained than with the commercial additives.

Another process in which the polymer solutions are useful is inflocculating and separating sewage. Polyether polyelectrolytes of thisinvention may also be used to break petroleum emulsions to separate theoil phase from the water phase and to coagulate polymeric latices.

The following specific examples illustrate typical methods by which thepolyelectrolytes of this invention may be made and processes in whichthey are useful. The examples are intended only to provide a clearerunderstanding of the invention and not to be considered as limiting itsscope.

EXAMPLE I This example illustrates preparation of one of thepolyquaternary ammonium salts used to prepare the chain-extendedpolyelectrolytes of this invention.

In a reaction vessel, 3.5 moles of dimethylamine (aqueous solution) wereadded to 1.0 moles of epichlorohydrin, with the temperature beingmaintained at 28 to 30C. during the addition of the epichlorohydrin.Then the contents of the vessel were heated to 65C. and held at thistemperature for 4 hours.

After the reaction, 1.0 mole of sodium hydroxide was added to thereaction vessel. The reaction mixture was then vacuum stripped to removewater and excess dimethylamine; The residue, a salt slurry, wasextracted with 1.35 moles of ethanol to remove the ditertiary amineproduct. The extract was flash distilled under vacuum to remove theethanol, leaving a residue which was vacuum distilled at a pressure of 5millimeters of mercury and at a temperature of 55 to 58C. to provide theproduct N,N,N',N'-tetramethyl-2-hydroxy- 1,3-propane diamine in a yieldof 53.6 percent.

Upon analysis, the product showed a purity of 99%*. To a reaction vesselwere added grams (0.993 moles) of the previously prepared N,N,N',N'-tetramethyl-Z-hydroxy-l,3 propane diamine (hereinafter referred to asTHPDA); grams (1.048 moles) of beta, beta.'-dichlorodiethylether(hereinafter referred to as DCEE); and 50 grams of water, withagitation. This mixture was heated to a temperature of 75 to 80C. andheld at thistemperature for a period of hours. Then an additional 150grams of water were added and the temperature of the reaction mixturemaintained at 75 to 80C. for an additional one-half hour. A polymericpolyquatemary ammonium salt product, containing repeating units of thefollowing formula:

was obtained and found to have a LVT Brookfield viscosity of 318centipoises measured at 23C. on a viscometer using a spindle No. 2. andspindle speed of 30 rpm and a solids content of 60.9 percent.

EXAMPLE ll EXAMPLE lll Another polymeric polyquatemary salt was preparedby following the procedure and conditions of Example I and by employing0.993 moles of Tl-lPDA and 0.984 moles of ethylene dibromide (EDB). Apolyquatemary polyammonium salt having a viscosity of 13.0 centipoisesat 23C. (N0. 1 spindle at 60 rpm.), a solids content of 63.0 percent,and containing repeating units of the following formula:

was obtained.

EXAMPLE lV Another poly(quaternary ammonium) salt having repeatingPolyquat units as illustrated in Example I was prepared in a commercialscale SOD-gallon reactor. In this case, 49 parts by weight of THPDA; 51parts by weight of DCEE and 16.25 parts by weight of water were chargedto the reactor and stirred. This mixture was heated to a temperature ofabout 176F. and maintained at this temperature for approximately 6hours. Also a pressure of 5 psig. was maintained with an inert gasmixture including nitrogen. The resulting product was steam stripped toremove unreactedDCEE. Then additional water (49.5 parts by weight) wasadded to adjust the viscosity. The final product had an LVT Brookfieldviscosity of 520 centipoises measured at 23C. on a viscosmeter using aNo. 2 spindle and a spindle speed of 30 rpm. and a solids content of55.6 percent. In the following examples this polymer solution is 10designated as Polyquat 55.6. At 33.0 percent solids, Polyquat 55.6 had aBrookfield viscosity of 52 centipoises. I

. EXAMPLE V A Poly(quaternary ammonium) 'Polyether Polyelectrolyte wasprepared in the following manner. Sodium hydroxide (8 grams) dissolvedin 40 millimeters of water was added to 100 grams of Polyquat 55.6stirred in a 500-milliliter reaction flask equipped with a mechanicalstirrer, thermometer, reflux condenser, and a nitrogen-blanketingdevice. The mixture was heated to 70C. and 40 grams of epichlorohydrin(hereinafter designated EPCHD) was added. A total of 125 milliliters ofwater was added to the stirred and heated mix ture to control viscosity,as follows: 5 milliliters at 10 minutes. The resulting poly(quatemaryammonium) polyether polyelectrolyte solution contained 31.9 percentsolids and had a Brookfield viscosity. of 500 centipoises at 23C. usinga No. 2 spindle at a spindle speed of 30 rpm. at pH 8.3. This is atenfold increase in viscosity over Polyquat 55.6.

The product has a structure containing repeating units of the followingstructure:

CHzCHOHCHz- 0-- +H r EXAMPLE VI The polyquatemary-ammonium salt preparedin Example Ill is treated with 35 grams of EPCl-lD per grams of polymersolution to yield a poly(quaternary ammonium) polyether polyelectrolyteof higher viscosity than the starting polymer. The structure of thispolyquatemary polyether has repeating units of the following formula:

CH CHOHCHg-O- EXAMPLE V blanketing means was added 8 grams of sodiumhydroxide dissolved in the amounts of water shown in the followingtable. The mixture was heated'to 70C and EPCI-ID was added as indicatedin the table.

Water in amounts varying from 125 to 225 milliliters was added to thereaction mixture continuously beginning immediately after the EPCHD wasadded with an initial amount of water, at a rate of 1.4 milliliters perminute using a 1 rpm. Emdeco intravenous injector pump. The stirredmixture was heated by a bath main- 1O TABLE 1 at a rate of 1.4milliliters per minute. in each experiment, 100 grams of Polyquat 55.6,35 milliliters of water, and 40 grams of EPCHD were charged-to thereaction vessel. The sodium hydroxide charge was varied as indicated inthe table below:

TABLE 2 Brookfield viscosity at NaOH Percent pH (alter Spindle Run N0.(grams) solids 12 hours) Cps. No. Rpm

These runs show that the amount of sodium hydroxide charged to thereaction mixture profoundly affects polymer properties. The highestviscosity product is obtained when about 8 grams of sodium hydroxide isused Total ad ditional water of dilution (ml.) (ml.)

Charged EPCIID (gr s) Spindle Brookiield viscosity at 23 C.

b 175 30.6 460 b 125 31 387 17 h 125 33 425 26. b 200 30. b 125 30. d175 36 b 225 32 125 28 a With NaOIl.

b At 1.4 mil. per minute.

= All above 125 milliliters at 1.4 ml. per minute as fast as possible.

d incrementally 25 mils. at 37 minutes of reaction; 15 mils. at 65minutes of reaction; 10 mils at 90 minutes of reaction.

It will be observed that at the higher EPCI-ID level, the viscosity wasimproved when the water was kept within certain levels. Thus, the datashow that the amount of water which is added to a 100 gram charge ofPolyquat 55.6 may vary within the range of about 40 100 to 400milliliters of water. This corresponds to between 29 and l 16 moles ofwater per mole of Polyquat 55.6 repeating unit. These experimentsfurther show that adding large amounts of water early in the reaction isdetrimental in that the solutions have lower viscosity than thoseobtained when water is added gradually during the course of a reactionrun.

EXAMPLE VIII Experiments in this Example show the relationship betweensodium hydroxide charged to the condensation reaction between Polyquat55.6 and EPCHD reactant and viscosities of the resulting polymersolutions. Each of the reactions was carried out withexternal heating at70C. and with 125 milliliters of water added per 100 grams of Polyquat55.6; this ratio corresponds to about 1.05 moles of sodium hydroxide permole of repeating Polyquat 55.6 unit. However, even polymer solutionsobtained when the sodium hydroxide ratio is from about 0.75 to about 1.6moles per mole of repeating Polyquat 55.6 units are higher in viscositythan the original higher-solids Polyquat 55.6 solution, i.e., 52centipoises.

EXAMPLE IX The experiments conducted in this Example show the effect onpolymer solution viscosity of the amount of water initially charged tothe reaction vessel in order to dissolve sodium hydroxide. In each case,the reaction was carried out at C. and a total of 125 milliliters ofwater was added at the rate of 1.4 milliliters per minute. Polyquat 55.6grams), 8 grams of sodium hydroxide, and varying amounts of EPCHD and ofwater i 55 were charged to the reaction vessel, as indicated in thefollowing table.

TABLE 3 Charged Brookfield viscosity at 23 C.

EPCHD Water Percent PII (alter Spindle (grams) (ml.) solids 12 hours)Cps. N0 Rpm 40 35 33. 1 8. 1 23,000 4 6 40 35 31. 9 8. 5 18, 500 4 6 4035 33. 9 8. 4 6,150 3 6 40 35 29. 9 8. 3 =1, 675 2 6 40 37 32.4 8.3 3201 6 40 40 35.0 7.) 215 1 6 20 35 29. 8 .1. 2 1, 200,000 4 3 20 37 31. .110.2 7,850 4 30 20 38 34. 0 11.8 340 1 G 20 39 33.4 i). 5 75 1 30 2O 4031.0 7.1 335 .2 30 15 34 30.8 10.4 7.5 1 60 15 37 211. (i 10. h 8 1 (i015 38 28. 7 10. 7 8.5 1 60 I This sample was further diluted withmilliliters of water.

When less than 35 milliliters of water was charged with the indicatedamounts of Polyquat 55.6 andsodium hydroxide at 40 grams of EPCHDcharged, gelatinous masses were obtained. v

Thus, for each 100 grams of Polyquat 55.6 and 40 grams of EPCHD charged,the highest product viscosities are obtained when about 35 millilitersof water are charged; this corresponds to about moles of water per moleof repeating Polyquat 55.6 units. At a charge of 100 grams of Polyquat55.6 and grams of EPCHD, the optimum ratio of water charged is aboutlO-ll moles of water per mole of repeating Polyquat 55.6 unit.

Wide variations in polymer solution viscosity, even under apparentlyidentical conditions, show the extreme sensitivity of the reactionbetween Polyquat 55.6 and EPCHD to the amount of water initiallypresent; These experiments further show that the amount of' waterinitially charged may vary in the range between 10 and 12 moles per moleof Polyquat 55.6 units in order to obtain products which have higherviscosities than the Polyquat 55.6 solutions but are still fluid. Itwill be appreciated, however, when the rate of water addition is raisedyou may .obtain a lower viscosity product even if the initial watercontent is lowered.

EXAMPLE x milliliters) was added at a rate of 1.4 milliliters perminute. To the reaction vessel were charged: 100 grams of Polyquat 55.6,8 grams of sodium hydroxide, 35 milliliters of water, and EPCHD invarying amounts. Results were:

TABLE 4 Brookfield viscosity at 23 0.

Run EPCHD Percent. pH (after Spindle N0. (grams) solids 12 hours) Cps.No. R.p.m.

a 225 milliliters of H10 added.

These experiments show that highly viscous gel-free solutions areobtained when from 20 to 40 grams of EPCHD are charged per 100 grams ofPolyquat 55.6; these EPCHD levels represent from 1.1 to about 2.3 molesof EPCHD per mole of Polyquat 55.6 units. It is also apparent that someslight viscosity increases are obtained, even at the lower solids levelof the chainextended polymer, when from about 0.55 to about 3.0 moles ofEPCHD are charged per mole of Polyquat 55.6.

EXAMPLE XI Experiments in this Example show the effect of temperatureduring the reaction between a poly(quaternary ammonium) polyelectrolyteand EPCHD on viscosities of the resulting polyrnef'solutions. The chargein each experiment was 100 grams of Polyquat 55.6, 8 grams of sodiumhydroxide, 35 milliliters of water and 40 grams of EPCHD. Additionalwater (125 milliliters) was added at a rate of 1.4 milliliters perminute.

TABLE 5 Brookfiold viscosity at.

pH (after Temp. Percent 12 hours) C.) solids 11.1mm.

x. 3 30 1 no G 100 l 12 1 23, 000 4 (l l 70 I 30 Run No. Cps.

EXAMPLE XII I Intrinsic viscosities [1;] were determined at'25C. in 0.4M KCl and 0.4 M'KBr for Polyquat 55.6 prepared in Example IV andfor theproducts from run 3 and 5 of Example IX. Results were:

TABLE 6 Solids 33.0

[1;] Brookfield 0.4M KBr 0.4M KCl Viscosity (cps.)

Source of Sample Polyquat 55.6

le IX,

30 A copolymer similar to Polyquat 55 .6 having the repeating unitstructure heretofore noted, i.e.

EXAMPLE XIII Selected poly(quaternary ammonium) polyetherpolyelectrolyte solutions prepared in the preceding Ex- 55 amples wereanalyzed for organic chloride and epoxide content. The chloride analysiswas done by the method described in Journal of the Association ofOfficial Agricultural Chemistry, Volume 44, page 595 (l96l)'and theepoxy analysis according to Analytical Chemistry, Volume 26,878 (1954).When the samples prepared in Example IV and in run 5 of Example IX wereextracted with heptane, there was a slight decrease in the amount oforganic chloride remaining. Treatment of an aliquot of the solutionprepared in Example VII, run 5 with 2N sodium hydroxide for 1 hour at30C. converted the chlorohydrin present quantitatively to epoxide. Theamount of organic chloride present as chlorohydrin, from the epoxidecontent of the sample, was 5.93 percent.

TABLE 7 Organic Chloride Source of Organic After Heptane Sample EpoxideChloride Extraction Example IV 0.43 7.50 6.09 Example IX Run 4 0.36 291Example IX Run 5 0.20 5.83 4.87 Example X Run 4 0.26 4.79 Example X Run2 0.23 2.45 Example X Run 5 0.4l 6.2] Example X Run 6 0.49 5.l7

- wanted reactions with substrates.

EXAMPLE XIV This Example illustrates the use of poly(quaternaryammonium) polyether polyelectrolytes of this invention as retention aidsin wet-end addition. Solka 30A bleached Northern Softwood Kraft wasbeaten to a Canadian standard freeness of 500 milliliters. To the pulpwas added 20 lbs. per ton of rosin, 50 lbs. per ton of aluminum sulfate,200 lbs. per ton of clay and 50 lbs. per ton of aluminum sulfate, 200lbs. per ton of clay and 50 lbs. per ton of titanium dioxide. The pH ofthe slurry was adjusted with sulfuric acid.

The slurry was agitated for 60 seconds after polyelectrolyte solutionwas added and then paper was made on a Noble and Wood hand sheet machineusing the pulp slurry to give a 5 gram sheet 8 inches square. The sheetshad a moisture content of 5 percent after drying. The sheets wereconditioned for 24 hours at 70F. and 50 percent relative humidity. Thepaper was examined for pigment retention.

In determining pigment retention, the sheets were fired for 2 hours at900C. The ash was cooled in a desiccator over Drierite (CaSO4) for about30 minutes and weighed. The percentage of ash, as indicated in thetables below, is a measure of the amount of pigment incorporated in thepaper.

These experiments show that the polyelectrolytes of this inventionfunction as efficient pigment retention aids in wet-end addition. Papersprepared using chainextended polyelectrolytes have, on the average,better than 40 percent pigment retention at a level of L0 lb. per ton atpH 6.0. This retention is significantly higher than that observed withPolyquat 55.6. In the testing at other pH levels, the polymericelectrolyte of this invention has been found to provide a significantlyhigher pigment retention level than other commercially availableretention aids. Good retention properties obtained appear to beessentially independent of polymer viscosity, once a threshold value ofaround 300 centipoises is exceeded.

EXAMPLE XV This Example shows the usefulness of polyetherpolyelectrolytes of this invention for clarifying white-water from papermaking. Evaluations were done in a laboratory simulation of a paper millfloatation unit in which fiber and pigments are lifted to the surface byair and the solids skimmed off. Ground wood fiber beaten to 50milliliters Canadian freeness, clay (50% by weight of the pulp), rosin,aluminum sulfate at a level of 50 lbs. per ton of pulp, and sodiumaluminate at a level of 1000 ppm were made up into the synthetic'wastewater mixture. The polymeric flocculant was added at the indicated leveland then 500 milliliters water pressurized with air at 50 lbs. persquare inch with air was added; the mixture was agitated and allowed tostand for one minute. A sample was taken at the midpoint and percentlight transmission at 530 millimicrons (mg) was determined. Thefollowing data was obtained.

(a) treated with air, no polymer present (b) Tylite No. 9 is a cationicpolymeric flocculant, a product of Pacific Resin Co.

These experiments show that both the poly(quaternary ammonium(polyelectrolytes used as starting materials in this invention and thechain-extended poly ether polyelectrolytes are efficient in white-waterclarification processes. The polyether polyelectrolyte has an efficiencycomparable to another commercially useful material.

EXAMPLE XVI This Example illustrates the use of the poly(quaternaryammonium) polyether polyelectrolytes of this invention for flocculationand separation of sewage. Solutions of the polyelectrolyte were added toraw sewage from Camden-Wyoming, Delaware having a solids content ofabout 0.5 percent and stirred for 3 minutes at rpm., for 10 minutes at35 to 40 rpm., for 10 minutes at 3 to 5 rpm. and the percenttransmission at 530 mp. was determined from a sample taken at themidpoint. The raw sewage had a transmission of 27.0%. In the table beloware given results for both the starting Polyquat 55.6 and the polymericflocculant prepared in Example IV.

TABLE 10 Transmission at 530m Level of Polymer (Polymer Added) Solution(ppm) Polyquat Solution from 55.6 Dow C-3w) Example W (31.9% Solids,

Viscosity 500 cps.) 1 43.0 40.5 44.0 3 44.5 40.0 45.8 5 46.0 40.7 47.050.5 42.0 52.5

(a) A polymeric coagulant which is a product of the Dow Chemical Co.

Advantageously, the chain-extended polymers of this invention are moreefficient than the starting Polyquat and a commercial material such asDow C-3l.

EXAMPLE XVII The experiments in this Example further illustrate theexcellent properties of polyether polyelectrolytes as flocculatingagents.

a. Flocculation studies were performed on English supreme Kaolin clay byplacing grams of clay in a 1000 milliliter graduated cylinder and addingwater to the top mark. One hundred milliliters of a polymer solution(including several of the polyelectrolytes heretofore used in thepreceding Example and a few known commercial products) was added and thesuspension was agitated by stirring manually for 1 minute to achieve auniform suspension. The time required for the settling meniscus, that isthe demarcation between the turbid and clear portions of the liquid, tofall from the 1,000 milliliter to the 600 milliliter graduation lineswas determined. The results are shown in Table l 1 below.

At equivalent levels of flocculant solution addition, it will beobserved that polyether polyelectrolyte solutions having a Brookfieldviscosity in excess of about 50 centipoises at a solids level of betweenabout 15 and about 35 percent are comparable or more efficient thanother products.

Even at levels as low as 1 part per million, polyether polyelectrolytesolutions in the 100 to 25,000 Brookfield viscosity range at about 30percent flocculate Kaolin slurries in a range varying from 250 to 370seconds. This time is shorter or compares favorably with that of thecommercial flocculants tested. At higher levels, such as in the 2 to 5ppm. range, the polymeric flocculants of the invention usually are moreefficient than the commercially available material; that is, the claysuspensions settle more rapidly when the polyelectrolytes of thisinvention are used. It is further seen that all polyetherpolyelectrolytes are more efficient flocculating agents than thestarting Polyquat 55.6 and that the more efficient and thus preferredrangeof solutions are those with Brookfield viscosities between 100 and25,000 cps. at between and 35 percent solids.

b. The amounts of flocculant solutions indicated in Table 12 below wereadded to Kaolin slurries prepared in part (a) and settling times weredetermined. Values aregiven in Table 12 below.

TABLE 12 Settling time in seconds Brookat varying dosages of fieldvlsflocculant (in ppm.)

Percent cosily of Flocculant (source) solids polymer 1 2 3 5 9 EX. VII,Run 3 17.0 1, 850 147 113 99' 94 Ex. VII, Run 5. 26. 3 52 160 108 98 8589 99 Ex. VII, Run 4. 33. 4 75 104 81 76 86 103 103 EX. VII, Run 9 32. 211 299 256 250 289 291 299 Ex. VII, Run 10 28. 7 8. 5 291 297 339 273378 Ex. VII, Run 2... 31. 9 7, 850 147 113 101 91 89 92 EX. VII, Run 130.6 545 123 91 79 84 88 Ex. VI, Run 7 30. 8 7. 5 321 308 401 Ex. IX,Run 12 31. 0 335 144 100 86' 75 78 82 Ex. IX, Run 10 34.0 340 126 93 8574 68 72 Ex. IX, Run14 29.6 8 314 321 Ex. IX, Run 7 33.1 89 106 86 82 8390 103 Tyllte N0. 9 106 79 71 5G 59 Cut-Flor: L 7-1 82 101 118 129Prodnct 01 Pacific Resin C0. Product of Calcon Co.

What is claimed is:

l. A process for flocculating a suspension of finely divided particlesin an aqueous medium which comprises mixing the aqueous medium with apoly(quaternary ammonium) polyether polyelectrolyte in amountssufficient to flocculate the particles within" said medium, saidpolyether polyelectrolyte comprising a polymer containing quaternarynitrogen atoms in a polymeric backbone and having repeating units of thefollowing generalized formula:

wherein R is an alkyl group containing from one-four carbon atoms; R iis the residue of a hydroxysubstituted lower alkylene group containingup to about 10 carbon atoms; R is an organic radical selected from thegroup consisting of an alkylene group containing one to four carbonatoms and a (CH ),,-O-(Cl-l group wherein n is an integer from 1 to 4;R' is an alkylene group containing one to four carbon atoms and R"" is aradical selected from the group consisting of an R residue of the sameor different polymeric chain or a terminal hydrogen, and A is an anionselected from the group consisting of chloride, bromide, and iodide.

2. The process of claim 1 in which the polyelectrolyte salt comprisesthe reaction product between a poly(- TABLE 11 Brookfield Settling timein seconds at varying dosage viscosof flocculant (in p.p.m.) FlocculantPercent ity of (source) solids polymer 1 2 3 4 5 6 7 9 Polyquat 55.6 55.6 52 651 650 645 642 640 Ex. XI, Run 1 31.3 30 460 423 405 392 385 31. 7290 247 225 210 200 32.4 250 170 120 110 29. 9 340 237 195 173 162 33. 9260 205 177 163 33. 1 370 305 268 245 230 29. 0 277 240 223 217 410 335298 280 270 263 260 .260 1 287 250 235 225 220 215 215 217 Tylite N'o. 9300 267 240 215 195 158 123 A product of Dow Chemical 00.polyothylcneimine. a product of Dow Chemical (0. .1 product of PacificResin (0.

quaternary ammonium salt) having a repeating unit of the generalizedformula:

with from 0.8 to 1.2 moles of an organic dihalide having the generalformula:

' AR-A and an epoxyhaloalkane reactive to hydroxyl groups in aqueoussolution with an alkaline agent present.

5. The process of claim 4 in which R is a methyl group, R is amethylidyne group, R" is an ethyleneoxyethylene group A is chloride, theepoxyhaloalkane is epichlorohydrin, and the alkaline agent is sodiumhydroxide.

6. The process of claim 1 in which said particles are inorganicmaterial.

7. The process of claim 1 in which said particles are organic materials.

8. The process of claim 1 in which said aqueous medium is apigment-containing slurry of paper-making fibers.

9. The process of claim 1 in which said finely divided particles in saidaqueous medium are clay.

10. The process of claim 1 in which said aqueous medium is sewage.

11. The process of claim 1 in which said aqueous medium is a polymerlatex.

12. The process of claim 1 in which said aqueous medium is white watereffluent from a paper-making operation.

2. The process of claim 1 in which the polyelectrolyte salt comprisesthe reaction product between a poly(quaternary ammonium salt) having arepeating unit of the generalized formula:
 3. The process of claim 2 inwhich the epoxyhaloalkane is selected from the group consisting ofepichlorohydrin; 1-bRomo-2, 3-epoxypropane; 1-chloro-3,4-epoxybutane;2-chloro-5,6-epoxyhexane; and 1,2-epoxy-6-iodohexane.
 4. The process ofclaim 1 in which the polyelectrolyte salt comprises the reaction productof a poly(quaternary ammonium) salt which is the reaction product from atetraalkylhydroxyalkylenediamine having the general formula:
 5. Theprocess of claim 4 in which R is a methyl group, R'' is a methylidynegroup, R'''' is an ethyleneoxyethylene group A is chloride, theepoxyhaloalkane is epichlorohydrin, and the alkaline agent is sodiumhydroxide.
 6. The process of claim 1 in which said particles areinorganic material.
 7. The process of claim 1 in which said particlesare organic materials.
 8. The process of claim 1 in which said aqueousmedium is a pigment-containing slurry of paper-making fibers.
 9. Theprocess of claim 1 in which said finely divided particles in saidaqueous medium are clay.
 10. The process of claim 1 in which saidaqueous medium is sewage.
 11. The process of claim 1 in which saidaqueous medium is a polymer latex.
 12. The process of claim 1 in whichsaid aqueous medium is white water effluent from a paper-makingoperation.